1. Field of the Invention
The present invention relates to computers or networks, and in particular, relates to maintaining information, such as security association information, in the event of a power loss.
2. Background Information
Computers or networks routinely and regularly xe2x80x9cback upxe2x80x9d a copy of files or data in nonvolatile storage media during the course of normal operation. Such protective measures are intended to save the copy of the data in a safe location, such that if a power failure occurs that damages or causes loss of the original data, the backup copy exists and can be retrieved to replace the damaged/lost original data.
However, existing methods of regularly making backup copies suffer from a number of disadvantages. First, data is often written to storage devices in its entirety. That is, for example, all of the data in a server may be backed up. This results in inefficient use of backup storage space and additional time to perform the back up process, particularly if there are types of data that do not require a backup copy.
Next, because power failures are unpredictable, data is generally backed up according to an established frequent schedule or routine, if at all. Again, this results in inefficiency because the frequency of power failures is many times less in order of magnitude than the number of times that backup processes are performed. In other words, thousands of backup processes may be performed in order to protect data against a single power failure that occurs infrequently. Performing these large numbers of write operations into a storage device can severely limit the longevity of the storage device by using up available storage space and by successively decreasing the number of write operations that the storage device can accommodate before it becomes unuseable/unwriteable.
Additionally, because a power failure can completely terminate power supplied to a computer or network, existing backup methods are performed while full power is available (e.g., before a power failure occurs), to ensure that sufficient power is present to complete the backup procedure. In some instances, a dedicated power supply is provided to specifically supply power to perform the backup procedures. Again, this results in inefficient use of resources.